This invention relates generally to heating and air conditioning systems and, more particularly, to a method and apparatus for operating such systems in an emergency power generating mode.
Power outages during the winter season due to severe weather, such as snow storms or freezing rain, have forced many residences and businesses to install additional emergency power equipment e.g. emergency generators and or batteries, in order to at least supply the power for essentials such as emergency lighting, heat (power to the furnace fan and controls), and for a refrigerator and freezer. These emergency power accommodations need to be permanently interconnected into the various components requiring power or interconnected when the power failure occurs and disconnected when power has been resumed. In either case, a substantial expense needs to be incurred in order to provide the necessary equipment which is seldom used.
A common arrangement of a comfort system for a residence or small business is the combination of an air conditioning and heating system with an evaporator coil, such as a so called A-coil, mounted in the top portion of a furnace such that the single blower can be used to alternatively circulate the air to be conditioned over a furnace heat exchanger or over the evaporator coil and then further distributed to the spaces to be heated or cooled. When a system is operating in the heating mode, the evaporator coil is disposed within the air flow path but is not active. Similarly, when operating in the cooling mode, the furnace heat exchanger lies within a path of the air being circulated by the fan, but the furnace heat exchanger is not heated.